ML19260D226
| ML19260D226 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 01/31/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 8002080142 | |
| Download: ML19260D226 (1) | |
Text
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NUCLEAR REGULATORY COMMISSION 3.o 3.
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1990 N. CALIFORNIA BOULEVARD
,o' SulTE 202, V/ALNUT CREEK PLAZA V/ALNUT CREE K, CALIFORNI A 94596 January 31, 1980 Docket No. 50-344 Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attention: Mr. Charles Goodwin, Jr.
Assistant Vice President Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recormlend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, L
nmd:
R. H. Engelken Director
Enclosures:
1.
IE Information Notice No. 80-03 2.
List of IE Information Notices Recently Issued cc w/ enclosures:
C. P. Yundt, PGE F. C. Gaidos, PGE J. W. Lentsch 1943 143 8002 80 /Af 1 0
UNITED STATES SSINS No.: 6870 NUCLEAR REGULAT0rtY COM:1ISSION Accession No.:
OFFICE OF INSPECTION AND EllFORCEMEflT 7912190666 WASHINGTON, D.C.
20555 January 31, 1980 IE Information Notice No. 80-03 MAIN TURBINE ELECTR0 HYDRAULIC CONTROL SYSTEf1 Description of Circunstances:
On September 6,1979, while performing a routine startup of the Trojan Nuclear Plant, a speed control problem was encountered during warnup of the General Electric turbine and increase of turbine speed to normal operating speed (1800 RPM). Technicians were notified and trouble shooting in accordance with the technical manual was comenced to resolve the apparent oscillation between the primary and backup speed control circuits which was hindering nomal turbine startup operations. The technical nanual indicates that it is permissible to renove either the primary or backup low value gate circuits which contain speed and acceleration error amplifiers. Upon removal of the primary low value gate circuit card, the backup card amplifiers, coming from a saturated condition, became the controlling circuit.
During the shift in control circuits (primary to backup), the speed / acceleration error signal went to maximun which resulted in a full open signal to the turbine control valves.
Under existing plant conditions this appeared to the safety injection systen as a major steam break downstream of the main steam isolation valves which resulted in a safety injection system actuation and reactor trip.
The Electrohydraulic Control System (EHC) technical manual indicated that slight load changes are likely when a low value gate card is removed. The effect on an unloaded turbine appears to be much nore significant and tests conducted by
- GEK Instruction Boo'; 11381-D, " Speed Control Unit", flaintenance Section, Page 4.
1943 144
I IE Information Notice flo. 80-03 January 31, ?9E0 Page 2 of 2 Trojan personnel indicate that the transient is initiated whether the turbine is at a set speed or in an acceleration mode to a set speed. Discussions with General Electric personnel by the licensee ha': en initiated in an attenpt to verify the phenomenon observed and, if apolicable, alert other facilities which operate a turbine with a f1K 1 EHC Syster, regarding the potential operation of the control valves when trouble shooting the speed control unit in accordance with existing instructions.
This information is provided as an early notification of a possible significant matter.
It is expected tha'. recipients will review the inforration for possible applicability to their facilities. fio specific action or response is recuested at this tire.
If further NRC evaluations so i'idicate, an IE Circular or Bulletin will be issued to recomend or reauest specific licensee uctions.
If you have questions regarding this matter, please contact the Director of the apprnpriate NRC Regional Office.
Enclosure:
List of Recently Issued IE Information flotices 1943 145
IE Information flotice flo. 80-03 Enclosure January 31, 1980 RECEflTLY ISSUED IE IflFORitATIO!! fl0TICES Infornation Subject Date Issued To flotice f:o.
Issued 80-02 8X8R Water flod Lower 1/25/80 All BWR Facilities End Plug Wear holder power reactor OLs or cps 80-01 Fuel Handlina Events 1/4/80 All holders of power reactor OLs and cps 79-37 Cracking in Low Pressure 12/28/79 All power reactor OLs Turbine f ics and cps 79-36 Computer Code Defect in 12/31/79 All power reactor OLs Stress Analysis of Piping and cps El bow 79-35 Control of l'aintenance 12/31/79 All power reactor facilities and Essential Equipment with an OL or CP 79-34 Inadequate Design of 12/27/79 All holders of power reactor Safety-Related Heat OLs and cps Exchangers 79-33 Improper Closure of 12/21/79 All power reactor facilities Primary Containment holding OLs and cps Access Hatches 79-32 Separation of Electrical 12/21/79 All oower reactor facilities Cables for HPCI and ADS holding OLs and cps 79-31 Use of Incorrect Anolified 12/13/79 All holders of power reactor Response Spectra (ARS)
CLs and cps 79-30 Reporting of Defects and 12/6/79 All power reactor facilities flancompliance,10 CFR Part 21.
holding OLs and cps and vendors inspected by LCVIP 79-29 Loss of flonSafety-Related 11/16/79 All power reactor facilities Reactor Coolant System holding OLs or cps Instrumentation During Opera tion 1943 146